This house was designed based on the results of more than 10 years of research and meets and exceeds all 10 criteria as outlined by "Bat Conservation International" bat certification program. Bat houses such as this tend to have higher occupancy rates than the smaller houses. The interior surface and landing platform is made of rough cut cedar make it easy for bats to cling when roosting and landing. The ventilation gap in the front of the house serves to maintain proper temperature and helps with air circulation. The roof is slanted forward at 30 degrees for better rain run-off. This bat house weathers beautifully as it is made of weather-resistant Western Red Cedar. The house is fully caulked and offers a longer design which is a key factor in occupancy. The 3/4" chamber give protection from predators, and deters wasp and hornets which prefer 1 1/2" chambers. The chamber is also constructed with rough cut cedar which provide great grasping points for bats. Proper bat house design is a very important factor in occupancy. This design has been proven to have a greater than 80% occupancy rate. Triple-celled bat houses tend to work quicker and for longer periods (i.e. throughout spring, summer, and fall). Comes with mounting instructions/screws Hand made in the USA